I dont know any better exercise for the core than overhead squats, both with barbell and single dumbell. A very distant second would be weighted controlled incline sit-ups, but that is a very distant second.
I "discovered" overhead squats late in life-maybe 6 years ago-something like that. Looking back in my training journal, I was starting to "stall" a bit on the big lifts-squat, deadlift, powerclean, etc and was wondering if the 40+ bug had hit me and that my best years were behind me, at least on the big lifts....along came Dan John's article and I gave OHS a shot....there is a learning curve involved...took me 5-6 sessions to get them down, but within two weeks, I saw an IMMEDIATE difference, especially in my squats. I can remember doing a particular weight for say 5 reps and having to "grind" them out, slowly and painfully, two weeks later I am doing 7 smooth reps with the same weight and you know how sometimes you finish a set and you feel like you just went 3 rounds with Brad Morris...(had the crap beat out of you) and other times, you finish a set and you are so energized that you actually "think" you could go three rounds with Brad...welll, that is how I felt after my set that day and just about every day since then.
I was a 700 plus drug free squatter early in my life and I retired from competitive lifting fairly early in life. I say without hesitation that if I had learned OHS as a teenager, I am confident that I would have squatted 800 at about the same age, give or take a year.
anyway, I like overhead squats....
